This article explains the phonology of the Malay language based on the pronunciation of Standard Malay, which is the official language in Brunei, Indonesia (as Indonesian), Malaysia (as Malaysian), and Singapore.
The consonants of Standard Malay and also Indonesian are shown below. (Non-native consonants that only occur in borrowed words, principally from Arabic and English, are shown in parentheses.) Some analyses list 19 "primary consonants" for Malay, being the 18 symbols that are not in parentheses in the table as well as the glottal stop [ʔ].
Orthographic Note: The sounds are represented orthographically by their symbols as above, except:
- /ɲ/ is <ny> before a vowel,<n> before <c> and <j>
- /ŋ/ is <ng>
- the glottal stop [ʔ] is final <k> or an apostrophe '
- /tʃ/ is <c>
- /dʒ/ is <j>
- /ʃ/ is <sy>
- /x/ is <kh>
- /j/ is <y>
- /p/, /t/, /k/ are unaspirated, as in the Romance languages, or as in English spy, sty, sky. In word-final position, they are often unreleased, with final /k/ generally being realised as a glottal stop in native vocabulary. There is no liaison, that is, no audible release even when followed by a vowel in another word, as in kulit ubi ('tapioca skins'), though they are pronounced as a normal medial consonant when followed by a suffix.
- The glottal stop [ʔ] may be represented by an apostrophe in Arabic derived words such as Al Qur'an.
- /h/ is pronounced clearly between like vowels, as in Pahang. Elsewhere it is a very light sound, and is frequently silent, as in hutan ~ utan ('forest'), sahut ~ saut ('answer'), like Romance languages. The exception to this tendency is initial /h/ from Arabic loans such as hakim ('judge').
- /r/ varies significantly across dialects. In addition, its position relative to schwa is ambiguous: kertas ('paper') may be pronounced [krəˈtas] or [kərəˈtas]. The trill /r/ is sometimes reduced to a single vibration when single, but it remains potentially a trill, not a flap [ɾ], single trill is pronounced between trill [r] and flap [ɾ].
- /f/, /ʃ/, /v/, and /z/ only appear in loanwords. Some speakers pronounce /v/ in loanwords as [v], otherwise it is [f]. [z] can also be an allophone of /s/ before voiced consonants.
Apart from the above, there are a few consonants from Arabic that are used by a small number of speakers.
Loans from Arabic:
- Phonemes which occur only in Arabic loans may be pronounced distinctly by speakers who know Arabic. Otherwise they tend to be substituted with native sounds.
Table of borrowed Arabic consonants
||khabar [ˈhabar], kabar [ˈkabar] "news"
||redha, rela "good will"
||lohor, zohor "noon (prayer)"
||ghaib, raib "hidden"
||saat, sa'at "time"
Nasal assimilation 
Important in the derivation of Malay verbs and nouns is the assimilation of the nasal consonant at the end of the derivational prefixes meng- /məŋ/ 'verbal prefix' and peng- /pəŋ/ 'nominal prefix'. The nasal segment is dropped before sonorant consonants, the nasals /m, n, ɲ, ŋ/, the liquids /l, r/ and the approximants /w, j/. It is retained before and assimilates to obstruent consonants: labial /m/ before labial /p, b/, alveolar /n/ before alveolar /t, d/, post-alveolar /ɲ/ before /tʃ, dʒ/ and /s/, and velar /ŋ/ before other sounds, velar /k, ɡ/ as well as /h/ and all vowels.
In addition, following voiceless obstruents, apart from /tʃ/ (that is /p, t, s, k/), are dropped.
That is, meng- produces the following derivations:
Table of nasal assimilation
It is usually assumed that there are six vowels in Standard Malay and also Indonesian. These six vowels are shown in the table below. However, it is also possible to set up a system with other vowels, particularly the open-mid vowels /ɛ/ and /ɔ/.
- Close vowels are close-mid in closed final syllables of root morphemes.
- In open final syllables of root morphemes, /a/ is generally pronounced as [ə] in peninsular Malaysian and in Singapore and Sumatra but not in Sarawak, Sabah, Brunei or in Indonesian. This also happens to the penultimate syllable if it is followed by /h/ such as usaha [usəhə].
- The front vowel /e/ and back vowel /o/ may vary between different speakers as they are popularly pronounced as close-mid in Malaysian and mid in Indonesian. In closed final syllables of root morphemes, the front vowel /i/ and back vowel /u/ are usually pronounced as [e] and [o], respectively, in Malaysian (except East Malaysia) and Malay of Singapore and Sumatra (where the language is native), and [ɪ] and [ʊ] in Indonesian; [e] and [o] are also allophones of /i/ and /u/ in closed final syllables in Malaysian, Singapore and Sumatra and [ɪ] and [ʊ] are allophones of /i/ and /u/ in Indonesian. [e] and [o] are distinct phonemes of other native words in all Malay dialects and in Arabic, Persian, Portuguese, English, Dutch, and Javanese loan words, and in foreign names. /i/ and /u/ are pronounced the same in Brunei and East Malaysia (Sabah and Sarawak).
- One source of variation in Malay is whether final /a/ in words such as saya ('I') is pronounced as [a] or as [ə]. So called 'a-varieties' pronounce it as [a], while 'schwa-varieties' pronounce it as [ə].
- Some words borrowed from English have the vowels [ɛ] and [ɔ], such as pek [pɛk] ('pack') and kos [kɔs] ('cost'). Words borrowed earlier have a more nativized pronunciation, such as pesta ('fest'), which is pronounced [pestə]. In Indonesian, [ɛ] and [ɔ] are allophones of /e/ and /o/ in closed final syllables.
- Some district dialects differentiate close-mid and open-mid (front and back) vowels. Examples are in the Kedahan dialect:
- [modɛ] (modal) ('modal')
- [bɔrak] (bohong) ('lie')
- [ɑ] is an occasional allophone of /a/ after or before more carefully pronounced consonant from Arabic words. Example: qari [qɑri].
- Some district dialects differentiate open front and back vowels. Example: [ɡulɑ] (gulai, the Perak River dialect).
- /a/ does not change to [ə] in singing, though /u/ and /o/ regularly changes to [ɯ] and [ɤ] respectively in urban singing. For example, aku ('I') is sung as [akɯ].
Some analyses claim that Malay has three native diphthong phonemes only in open syllables, they are:
- /ai̯/: kedai (shop), pandai (clever)
- /au̯/: kerbau (buffalo)
- /oi̯/ or /ʊi̯/: dodoi, amboi
Others assume that these "diphthongs" are actually a monophthong followed by an approximant, so 'ai' is /aj/, 'au' is /aw/, and 'oi' is /oj/. On this basis, there are no phonological diphthongs in Malay.
Words borrowed from English with /eɪ/, such as Mei ('May') and esei ('essay') are pronounced with /e/. This feature also happens to English /oʊ/ which becomes /o/.
Diphthongs are differentiated from two vowels in two syllables, such as:
- /a.ʔi/: rai ('celebrate') [ra.ʔi], kain ('cloth') [ka.ʔen] or [ka.ʔɪn] or [ka.in], air ('water') [a.ʔer] or [a.ʔɪr] or [a.ʔir]
- /a.ʔu/: bau ('smell') [ba.ʔu], laut ('sea') [la.ʔot] or [la.ʔʊt] or [la.ʔut]
Even if it's not differentiated in modern Rumi spelling, diphthongs and two vowels are differentiated in the spelling in Jawi, where a vowel hiatus is indicated by the alphabet hamzah (ء); example: لاءوت laut (sea).
The vowel hiatuses below are two different vowels but pronounced as diphthongs.
- /ia/: meriah ('lively')
- /iu/: liur ('saliva')
- /ua/: luar ('outside')
- /ui/: kelui ('paging')
Malay has light stress that falls on either the final or penultimate syllable, depending on regional variations as well as the presence of the schwa (/ə/) in a word. It is generally the penultimate syllable that is stressed, unless its vowel is a schwa /ə/. If the penult has a schwa, then stress moves to the ante-penultimate syllable if there is one, even if that syllable has a schwa as well; if the word is disyllabic, the stress is final. In disyllabic stress with a closed penultimate syllable, such as tinggal ('stay') and rantai ('chain'), stress falls on the penult.
However, there is some disagreement among linguists on whether stress is phonemic (unpredictable), with some analyses suggesting that there is no underlying stress in Malay.
Classification of languages into different rhythmic classes can be problematic. Nevertheless, acoustic measurements suggest that Malay has more syllable-based rhythm than British English, even though doubts remain about whether the syllable is the appropriate unit for the study of Malay prosody.
Syllable Structure 
Most of the native lexicon is based on disyllabic root morphemes, with a small percentage of monosyllabic and trisyllabic roots. However, with the widespread occurrence of prefixes and suffixes, many words of five or more syllables are found.
Syllables are basically CVC, where the V is a monophthong and the final C may be an approximant, either /w/ or /j/. (See the discussion of diphthongs above.)
Historical Change 
- Middle /w/ → Middle /b/
- /t͡ʃ/ → /c͡ç/ → /c/
- /d͡ʒ/ → /ɟ͡ʝ/ → /ɟ/
- Final /ʔ/ → Final /k/
- ^ a b c d e Clynes, A., & Deterding, D. (2011). Standard Malay (Brunei). Journal of the International Phonetic Association, 41, 259–268.On-line Version
- ^ a b Soderberg, C. D., & Olson, K. S. (2008). Indonesian. Journal of the International Phonetic Association, 38, 209–213.
- ^ Asmah Haji Omar (2008). Ensiklopedia Bahasa Melayu. Kuala Lumpur: Dewan Bahasa dan Pustaka, page 108.
- ^ Yunus Maris, M. (1980). The Malay Sound System. Kuala Lumpur: Penerbit Fajar Bakti Sdn. Bhd, page 52.
- ^ This is the argument for the nasal being underlyingly /ŋ/: when there is no place for it to assimilate to, it surfaces as /ŋ/. Some treatments write it /N/ to indicate that it has no place of articulation of its own, but this fails to explain its pronunciation before vowels.
- ^ Asmah Haji Omar (2008). Ensiklopedia Bahasa Melayu. Kuala Lumpur: Dewan Bahasa dan Pustaka, page 97.
- ^ Yunus Maris, M. (1980). The Malay Sound System. Kuala Lumpur: Penerbit Fajar Bakti Sdn. Bhd, page 2.
- ^ Asmah Haji Omar. (1977). The phonological diversity of the Malay dialects. Kuala Lumpur: Dewan Bahasa dan Pustaka.
- ^ Clynes, A. (1997). On the Proto-Austronesian ‘diphthongs’. Oceanic Linguistics, 36, 347–362.
- ^ a b Zuraidah Mohd Don, Knowles, G., & Yong, J. (2008). How words can be misleading: A study of syllable timing and "stress" in Malay. The Linguistics Journal 3(2). See here
- ^ http://email.eva.mpg.de/~gil/ismil/11/abstracts/Gil.pdf Gil, David. "A Typology of Stress, And Where Malay/Indonesian Fits In" (abstract only)
- ^ Roach, P. (1982). On the distinction between 'stress-timed' and 'syllable-timed' languages. In D. Crystal (Ed.), Linguistic Controversies (pp.73–79). London: Edward Arnold.
- ^ Deterding, D. (2011). Measurements of the rhythm of Malay. In Proceedings of the 17th International Congress of Phonetic Sciences, Hong Kong, 17–21 August 2011, pp. 576–579. On-line Version
- ^ Adelaar, K. A. (1992). Proto Malayic: The reconstruction of its phonology and parts of its lexicon and morphology. Canberra: Pacific Linguistics.